how to make our own function like touch in c++ - c++

Question

As soon as I add the below code this programs ends showing this error message:
Process returned -1073741819 (0xC0000005)
If I run those code separately then both of them work.
I used sstream and array too but combined they do not work properly.
#include <sstream>
#include <string>
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
string input = "touch world.txt this.txt is.txt sentence.txt";
string word;
int length = 0;
for(int a = 0;a<input.length();a++){
if(input[a] == ' '){
length++;
}
}
string filesNameArr[length];
int number = 0;
// hello world this is sentence
for(auto x:input)
{
if(x==' ')
{
filesNameArr[number] = word;
word.erase();
number++;
}
else
word=word+x;
}
filesNameArr[number] = word;
number = 0;
//when i add the below code it generates error and stops
ofstream outFile[41];
stringstream sstm;
for (int i=0;i<41 ;i++)
{
sstm.str("");
sstm << "subnode" << i;
outFile[i].open(sstm.str().c_str());
}
return 0;
}

Answer 1

length is one less than the number of words in your string as you are only counting the number of spaces. This means your final filesNameArr[number] = word causes undefined behaviour and will probably corrupt the stack.
string filesNameArr[length]; uses a variable length array which is not valid c++. If you use a std::vector instead you can skip the initial counting of the words completely:
std::vector<std::string> filesNameArr;
for(auto x:input)
{
if(x==' ')
{
filesNameArr.push_back(word);
word.erase();
}
else
{
word+=x;
}
}
filesNameArr.push_back(word);
You can use std::stringstreams built in ability to read words from strings to make this even simpler:
std::stringstream sinput(input);
std::vector<std::string> filesNameArr;
std::string word;
while (sinput >> word)
{
filesNameArr.push_back(word);
}